I rotate. A little of it is done for soil reasons, but it is mostly done to try and stay ahead of the insects! If the field sits in the same spot for more than a couple of years in a row, white fly and other such nasties get pretty established. I'd just as soon not have to use any more spray than minimally necessary & rotating helps greatly (here, for me, in my experience, etc. :-) -Jim C Mild to Wild